Model skull



FIG. 1 is a front elevation of a model skull showing our new design;

FIG. 2 is a perspective view from one side;

FIG. 3 is a side elevation;

FIG. 4 is a plan view from below;

FIG. 5 is a plan view from above;

FIG. 6 is a rear elevation. 

The ornamental design for a model skull, substantially as shown and described. 